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28 Cards in this Set
- Front
- Back
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What are the features of Eukaryotic cells?
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DNA w/ nuclear membrane
Mitotic Division More than 1 chromosome Membrane bound organelles 80S Ribosome No cell wall or cell wall w/chitin (fungi) Sexual reproduction via meiosis |
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What are the features of Prokaryotic cells?
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No nuclear membrane or nucleoli
Binary Fission Division 1 Chromosome 70S Ribosome Cell wall containing peptidoglycan Sexual reproduction via conjugation |
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What are cilia?
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-Fine, hair-like projections from certain cells
-Can be used for locomotion |
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How are viruses different from other cells?
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Nucleic acid can be DNA or RNA
Outer surface is a protein capsid & lipoprotein envelope NO - cells, nucleus, ribosomes, mitochondria, motility |
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How do eukaryotic cells reproduce?
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Mitosis - replication & dividing of chromosomes to make identical daughter cells
PMAT - Prophase Metaphase Anaphase Telophase Budding |
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How do prokaryotic cells reproduce?
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Binary Fission -single DNA replicates& attaches each copy to a different part of the cell memebrane; cell pulls apart and splits (cytokinesis) and two identical cells are created
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How do viral cells replicate?
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Adsorption:
Penetration Uncoating / Eclipse Phase Viral Genome Replication Maturation Release |
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What are the properties that make a cell wall Gram + ?
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Thicker peptidoglycan layer
Some have teichoic acid fibers that protrude out |
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What is endotoxin on Gram - cells?
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Lipid polysaccharide composed of Lipid A
Responsible for many disease features -fever, shock, etc |
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What are the properties that make a cell wall Gram - ?
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LPS, lipoproteins, Phopholipids (lipid A)
Periplasmic space btwn the outer layer & cytoplasmic membrane Endotoxin |
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What is peptidoglycan?
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Complex interwoven network surrounding the entire cell
Composed of single covalently linked macromolecule Thick & multilayered in Gram + Thin & single layered in Gram - |
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What is the function of peptidoglycan?
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Rigid support for cell - maintains shape
Good target for antibacterial drugs |
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What are teichoic acids?
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Antigenic
Induce antibodies that are specific |
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What is Lipid A?
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phospholipid responsible for toxic effects of Gram - infections
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What bacteria is not surrounded by a cell wall?
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Mycoplasm
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What is the periplasmic space?
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Space btwn plasma membrane & outer membrane in Gram - bacteria
Site of beta-lactamase enzymes that degrade PCNs & other beta-lactam drugs |
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What are beta-lactamases?
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Bacterial enzyme that catalyzes the hydrolysis of the beta-lactam ring in some PCNs, rendering them ineffective
Located in the periplasmic space of Gram - |
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How do you differentiate Gram - and Gram + bacteria on a Gram Stain?
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Gram + will be blue
Gram - will be red |
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What is the process of Gram Staining?
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Crystal Violet stains all cells blue
Iodine solution is added to form crystal violet-iodine complex Organic Solvent (alcohol or acetone) extracts blue dye from Gram - Red Safranin Dye stains Gram - cells red; not taken up by Gram + |
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What part of the Gram + cell allows it to stain differently from Gram - ?
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thick peptidoglycan layer
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What is the capsule of bacteria composed of ?
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Polysaccharide - gelatinous structure
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What is the quelling reaction?
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ID of an organism can be made using antiserum against the capsular polysaccharide. In the presence of homologous antibody the capsule will swell. Swelling is used to ID the organism
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What is the function of mesosomes?
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Current thought is no fxn
Previously was thought to fxn in DNA replication & cell division or excretion of exoenzymes |
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What are plasmids?
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Extrachromosomal, dbl stranded, circular DNA molecules
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What is the function of plasmids?
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Capable of replicating independent of the bacterial chromosome
Can be integrated into the bacterial chromosome Bacteria can absorb the plasmid into the cell Helps bacteria adjust to their environment - immunity to abx |
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What are transposons?
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Pieces of DNA that move readily from one site to another within or btwn DNAs of bacteria, plasmids, & bacteriophages
Not capable of independent replication Code for resistance & mutations |
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What is the medical importance of bacterial spores?
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Resistant to heat and chemicals - sterilization is difficult
Abx are ineffective against spores b/c the are metabolically inactive |
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How/Why are bacterial spores formed?
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Form in response to adverse conditions;
Gram + rods, bacillus & clostridium Have a thick keratin-like coat |
